Capsule part for a coffee capsule

ABSTRACT

A coffee capsule which contains a capsule part is configured to receive roasted and ground coffee and is suitable for preparing an espresso beverage using pressurized hot water in an espresso machine. The capsule part is a frustoconical plastics part with a conical side wall and an outwardly protruding peripheral flange integrally formed on the large frustoconical diameter. The peripheral flange has a peripheral external thickened portion. A tearable membrane is able to be welded onto an internal peripheral welding surface of the peripheral flange. A radially extending bellows is present between the welding surface and the peripheral external thickened portion. The bellows can be plastically and/or elastically deformed while maintaining a sealing effect with radial and axial tolerance compensation for a brewing chamber-closing device of the espresso machine.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to currently pending Swiss Patent Application Serial No. CH-00195/13 filed Jan. 17, 2013.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

FIELD OF THE INVENTION

The present invention relates generally to a coffee capsule that is configured to receive roasted and ground coffee and being suitable for preparing an espresso beverage using pressurized hot water in an espresso machine and also more specifically to a part of such coffee capsule.

BRIEF DESCRIPTION OF THE INVENTION

Aspects and advantages of the invention are set forth below in the following description, or may be obvious from the description, or may be learned through practice of embodiments of the invention.

Coffee capsules of this type are known in principle, in particular from the portion packs for coffee preparation from Nestlé SA of Switzerland for espresso machines. The capsules thereof, as well as compatible products, in principle contain a capsule part which is a substantially frustoconical metal or plastics part, with a conical side wall, a top part integrally formed on the small frustoconical diameter and an outwardly protruding peripheral flange integrally formed on the large frustoconical diameter. The peripheral flange thus has a surface on the top part side and an outlet clamping surface opposing the surface on the top part side. Additionally, the peripheral flange has a peripheral external thickened portion as a centring aid and a peripheral welding surface on the outlet clamping surface, onto which a tearable membrane is able to be welded.

During operation, in other words during the preparation of a coffee beverage in the espresso machine, the coffee capsule is located in a so-called brewing chamber, which is also of frustoconical shape and which is kept shut by a counterpressure plate. The counterpressure plate is provided with puncture teeth or perforation teeth in order to puncture the tearable membrane of the coffee capsule under the action of the pressure built up in the capsule after closing the brewing chamber and thereby to permit the brewed coffee beverage to flow out. Additionally, the counterpressure plate also has outlet openings through which the coffee beverage is able to enter a beverage dispensing channel. In the brewing state, the peripheral flange of the coffee capsule is clamped and centred between the brewing chamber and the counterpressure plate. Naturally, the result of this design is that the seal at the clamping point between the brewing chamber, the peripheral flange of the coffee capsule and the counterpressure plate has to be ensured during operation, as otherwise undesired leakages or bypass flows occur at this point. An at least partial seal may naturally already be achieved by a sufficiently high clamping pressure between the brewing chamber and the counterpressure plate. In principle, however, various other measures may be provided to achieve the desired seal, either on the coffee capsule or on the espresso machine itself.

The sealing means on the espresso machine may, for example, consist in the pressure chamber and/or the counterpressure plate being able to be provided with sealing rings or similarly acting means. A drawback with these solutions is that their sealing effectiveness degrades because they wear relatively rapidly or seat incompletely due to soiling.

For this reason, although sealing means are preferably used on the coffee capsules themselves, they have the drawback that they increase the cost of producing the capsules. The known and currently marketed Nespresso brand coffee capsules made of aluminium from Nestlé, however, have no additional and/or separately and locally applied sealing elements in the projection region of the flange. A sufficient seal in this case is produced by other means about which no further details will be provided here as the solution has practically no common features with the present invention.

In the area of sealing means which are suitable for the capsule, however, appropriate solutions have been proposed. Thus, for example, EP-1 654 966 reveals a solution in which, for example, rubber-elastic seals are attached to the surface of the flange on the top part side in order to achieve the desired seal at least in this partial region. As already mentioned, the capsules thus produced naturally become more expensive as additional materials and operations are required during production.

However, it has been clearly shown that the problem of the seal in the capsule region is becoming increasingly significant. On the one hand, this is because Nespresso-compatible coffee capsules are increasingly used where the capsules and the brewing chamber do not coincide exactly in size or in shape. This means that undesired bypass paths might occur and that, due to the pressure difference which is to be expected in principle between the capsule inlet and capsule outlet, said bypass paths have the effect of increasing the problem. As Nespresso-compatible coffee capsules are also increasingly made of plastics material, naturally also the problem of the dimensional stability of the capsules themselves is intensified, as said plastic capsules are still able to be deformed further when welding-on or attaching the membrane, for example. Added to this are the production tolerances of the brewing chamber closing device which are in any case present and the appearance of wear and soiling in the sealing region, i.e., between the brewing chamber and the counterpressure plate closing the brewing chamber. A suitable design of a coffee capsule that accommodates all these tolerances, even with different types of design of the frustoconical part of the capsule part, has thus far proved elusive.

SUMMARY OF EMBODIMENTS OF THE INVENTION

It is, therefore, a principal object of the invention to provide for a coffee capsule, a novel design for a capsule part that has the greatest possible sealing effect, with radial and axial tolerance compensation for a brewing chamber-closing device of an espresso machine. In satisfying this object, the invention is in no way restricted from solving additional problems encountered in the art.

With a generic coffee capsule and/or a capsule part which the coffee capsule contains, the solution in accordance with the present invention employs a radially extending bellows disposed between the welding surface thereof, which is arranged on the inside, and the peripheral external thickened portion. The bellows is able to be plastically and/or elastically deformed and has a sealing effect with radial and axial tolerance compensation for a brewing chamber-closing device of the espresso machine.

Naturally, the main advantages of such a design are that a sealing means which is suitable for a capsule is provided. This sealing means does not require additional and/or separate and locally applied sealing elements in the projection region of the flange and, due to its capacity for high radial and axial tolerance compensation, is suitable for a plurality of different capsule designs made of plastics material. Naturally, a cost advantage is thus also achieved due to the simple production.

A radially extending bellows has an improved capacity for radial and axial tolerance compensation relative to the sealing action because a number of multiple sealing points may be formed on the sealing edges. These multiple sealing points are repeated concentrically and thus increase in their effect and deal much more effectively with the local conditions between the brewing chamber and the counterpressure plate than the previous conventional flange designs, which have much less clearance for plastic and/or elastic deformability.

The radially extending bellows itself may naturally also be designed differently according to requirements. Thus, it may have a different number of sealing edges, and the sealing edges in turn may be produced from cross sections of, for example, zigzag shaped or wave-shaped design or even a design consisting of a mixture of shapes.

Moreover, the bellows may be arranged relative to the welding surface with different axial offsets. By combining and varying these features, the compatibility and sealability of the coffee capsule may be further improved according to requirements of any of a variety of expresso machines.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof to one skilled in the art, is set forth more particularly in this specification, including reference to the accompanying figures, in which:

FIG. 1 shows a side view of a capsule part with a flange according to the invention,

FIG. 2 shows an enlarged view of a partial section in the flange region of a capsule part according to FIG. 1 in an arrangement between a brewing chamber and a counterpressure plate, and

FIG. 3 shows an alternative offset arrangement of the bellows relative to the welding surface.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Reference will now be made in detail to present embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and letter designations to refer to features in the drawings. Like or similar designations in the drawings and description have been used to refer to like or similar parts of the invention.

Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present invention without departing from the scope or spirit thereof. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

FIG. 1 shows a side view of a capsule part 1 according to an embodiment of the invention of a coffee capsule 2 with a flange 3. The capsule part 1 in this case is a substantially frustoconical plastics part with a conical side wall 4. The capsule part 1 has a top part 5 integrally formed on the small frustoconical diameter, whilst the outwardly protruding and peripheral flange 3 is integrally formed on the large frustoconical diameter. The partial region A marked with a circle in FIG. 1 is shown in an enlarged detail in FIG. 2. The complete coffee capsule 2 consists of the capsule part 1 and the membrane 12 attached thereto. Also, as schematically shown in FIG. 1, the hollow capsule part 1 is hollow and is configured to receive roasted and ground coffee and is suitable for preparing an espresso beverage using pressurized hot water in an espresso machine. A portion of the conical side wall 4 has been cut away in FIG. 1 to reveal a filling 20 consisting of roasted and ground coffee disposed in the hollow capsule part 1.

FIG. 2 shows an enlarged view of a partial section in the flange region of a capsule part 1 according to FIG. 1. The partial region A marked in FIG. 1 is shown. The FIG. 2 view shows the arrangement of the coffee capsule 2 between a brewing chamber 6 of the espresso brewing machine and a counterpressure plate 7 during a brewing process in an espresso machine. A brewing chamber closing device (not shown) of the espresso machine ensures that the brewing chamber 6 and the counterpressure plate 7 during the brewing process are mutually pressed together by compressive forces schematically indicated by the arrows designated F in FIG. 2.

As shown in FIG. 2, the peripheral flange 3 has a surface 8 on the top part side and an outlet clamping surface 9 opposing the surface 8 on the top part side. Moreover, the peripheral flange 3 has a peripheral external thickened portion 10, which serves for centering the coffee capsule 2. Additionally, the outlet clamping surface 9 has an internally arranged peripheral welding surface 11 onto which a tearable membrane 12 is able to be welded.

In order to ensure correct welding of the membrane 12, even with slight deformations of the capsule part 1, the width of the welding surface 11 desirably is intended to be at least double the size of the wall thickness of the conical side walls 4 of the capsule part 1.

As shown in FIGS. 2 and 3, a radially extending bellows 13 is present between the welding surface 11 and the peripheral external thickened portion 10. The bellows 13 is configured so that it is able to be plastically and/or elastically deformed while maintaining a sealing effect with radial and axial tolerance compensation for the brewing chamber-closing device of the espresso machine.

In the present exemplary embodiment, the radially extending bellows 13 has a zigzag shaped cross section. Other cross sections extending in principle in a wave-shaped manner or even a mixture of shapes of different types of cross section are naturally also possible (for example combinations of zigzag shaped and wave-shaped paths).

It is also visible from FIG. 2 that the bellows 13 has so-called sealing edges 14. During a brewing process, said sealing edges 14 form the contact points of the surface 8 on the top side and the outlet clamping surface 9 of the flange 3 relative to the brewing chamber 6 and relative to the counterpressure plate 7, and thus they act as multiple sealing points. In the present exemplary embodiment of the bellows 13 therefore, at least two alternately opposing sealing edges 14 extending concentrically are provided.

It has been mentioned that the bellows 13, for example, may also have a wave-shaped cross section. Although in wave-shaped cross sections it is not possible to speak of actual edges, the contact points at the minimum and maximum points of these shapes naturally also have the effect of multiple sealing points, and thus such sealing points are also denoted the same, i.e., also as sealing edges 14.

Finally, for the sake of completeness, it also should be mentioned that the counterpressure plate 7 of the espresso machine is provided with puncture teeth or perforation teeth 15 as shown in FIG. 2. Under the pressure of the water flowing into the capsule 2, the tearable membrane 12 of the coffee capsule is deformed and is pressed onto the counterpressure plate 7. At the same time, the membrane 12 is punctured by the perforation teeth 15 to enable the brewed coffee beverage to flow out. To this end, the counterpressure plate 7 also has outlet openings 16 through which the coffee beverage is able to enter a beverage dispensing channel (not shown).

FIG. 3 finally shows a further alternative offset arrangement of the bellows 13 relative to the welding surface 11. For example, if the relative position of an imaginary center line 17 of the wave-shaped cross section of the bellows 13 is viewed in comparison with the position of the welding surface 11, it is visible from FIGS. 2 and 3 that the bellows 13 can have more than one different axial offset relative to the welding surface 11. In the solution according to FIG. 2, the imaginary centre line 17 of the bellows 13 is located in a plane above the plane in which the welding surface 11 is located. However, in FIG. 3, the imaginary center line 17 and/or center plane 17 is located in line with and thus coincident with the plane of the welding surface 11.

The person skilled in the art will recognize without difficulty that parameters are available in the disclosed embodiments, i.e., in the design of the cross section of the bellows 13 and in the choice of offset, and that by varying said parameters the best possible seal may be achieved in the problem area described for any given espresso machine configuration.

It also may be easily seen that, compared to the usual capsule designs, a radially extending bellows 13 designed according to the invention and which is able to be plastically and/or elastically deformed has a markedly improved capacity for high radial and axial tolerance compensation for a plurality of different capsule designs, as the formation of multiple sealing points, which has been described above, will prove effective even if the bearing surfaces and/or contact surfaces on the brewing chamber and on the counterpressure plate already have stuck-on deposits due to soiling thereof. 

What is claimed is:
 1. Capsule part for a coffee capsule consisting of the capsule part and a tearable membrane attached thereto, the coffee capsule being configured to receive roasted and ground coffee and being suitable for preparing an espresso beverage using pressurized hot water in an espresso machine, the capsule part comprising: a. a plastic frustoconical part having a conical side wall, a top part integrally formed on the small frustoconical diameter and an outwardly protruding peripheral flange integrally formed on the large frustoconical diameter, and b. the peripheral flange having a surface on the top part side and an outlet clamping surface opposing the surface on the top part side, the peripheral flange having a peripheral external thickened portion, c. the outlet clamping surface having a peripheral welding surface onto which the tearable membrane is able to be welded, and d. a radially extending bellows disposed between the welding surface and the peripheral external thickened portion, said bellows being able to be plastically and/or elastically deformed and having a sealing effect with radial and axial tolerance compensation for a brewing chamber-closing device of the espresso machine.
 2. Capsule part according to claim 1, wherein the cross-sectional shape of the bellows is one cross-sectional shape selected from one of the following: a zigzag shaped cross section and a wave-shaped cross section.
 3. part according to claim 2, wherein the bellows on the surface on each of the top part side and the outlet clamping surface has at least two concentric sealing edges alternately opposing one another and which form multiple sealing points.
 4. Capsule part according to claim 1, wherein the bellows on the surface on each of the top part side and the outlet clamping surface has at least two concentric sealing edges alternately opposing one another and which form multiple sealing points.
 5. Capsule part according to claim 4, wherein the bellows is arranged axially offset relative to the welding surface.
 6. Capsule part according to claim 3, wherein the bellows is arranged axially offset relative to the welding surface.
 7. Capsule part according to claim 2, wherein the bellows is arranged axially offset relative to the welding surface.
 8. Capsule part according to claim 1, wherein the bellows is arranged axially offset relative to the welding surface.
 9. Capsule part according to claim 8, wherein the width of the welding surface is at least double the size of the wall thickness of the capsule part.
 10. Capsule part according to claim 7, wherein the width of he welding surface is at least double the size of the wall thickness of the capsule part.
 11. Capsule part according to claim 6, wherein the width of the welding surface is at least double the size of the wall thickness of the capsule part.
 12. Capsule part according to claim 5, wherein the width of the welding surface is at least double the size of the wall thickness of the capsule part.
 13. Capsule part according to claim 4, wherein the width of the welding surface is at least double the size of the wall thickness of the capsule part.
 14. Capsule part according to claim 3, wherein the width of the welding surface is at least double the size of the wall thickness of the capsule part.
 15. Capsule part according to claim 2, wherein the width of the welding surface is at least double the size of the wall thickness of the capsule part.
 16. Capsule part according to claim 1, wherein the width of the welding surface is at least double the size of the wall thickness of the capsule part.
 17. Coffee capsule for preparing an espresso beverage using pressurized hot water in an espresso machine having a brewing chamber-closing device, the coffee capsule comprising: a. a hollow capsule part and a tearable membrane attached thereto, the hollow capsule part being configured to receive roasted and ground coffee and being suitable for preparing an espresso beverage using pressurized hot water in an espresso machine; b. a filling consisting of roasted and ground coffee disposed in the hollow capsule part; and c. wherein the hollow capsule part including: a plastic frustoconical part having a conical side wall, a top part integrally formed on the small frustoconical diameter and an outwardly protruding peripheral flange integrally formed on the large frustoconical diameter, ii. the peripheral flange having a surface on the top part side and an outlet damping surface opposing the surface on the top part side, the peripheral flange having a peripheral external thickened portion, iii. the outlet clamping surface having a peripheral welding surface onto which the tearable membrane is welded, and iv. a radially extending bellows disposed between the welding surface and the peripheral external thickened portion, said bellows being able to be plastically and/or elastically deformed and having a sealing effect with radial and axial tolerance compensation for a brewing chamber-closing device of the espresso machine.
 18. Coffee capsule according to claim 17, wherein the frustoconical capsule part and the membrane have aroma-preserving properties.
 19. Coffee capsule according to claim 18, further comprising a coating with aroma-preserving properties applied to the frustoconical capsule part and the membrane.
 20. Coffee capsule according to claim 19, wherein the coating has been sprayed onto the inside of at least one of the frustoconical capsule and the membrane.
 21. Coffee capsule according to claim 19, wherein the coating has been sprayed onto the outside of at least one of the frustoconical capsule and the membrane. 